Article treating machine with pneumatically operated safety interlock



June 6, 1961 FIG] ARTICLE J. BOCHAN TREATING MACHINE WITH PNEUMATICALLY OPERATED SAFETY INTERLOCK Filed 001;. 3, 1960 INVENTOR. J'OHN BOCHAN QQPW HIS ATTORNEY Unitcd States Patent 2,986,910 ARTICLE TREATING MACHINE WITH PNEU- MATICALLY OPERATED SAFETY INTERLOCK John Bochau, Louisville, Ky., assignor to General Electric Company, a corporation of New York Filed Oct. 3, 1960, Ser. No. 59,938 4 Claims. (Cl. 683) This invention relates to an article treating machine such as, for instance, clothes washing machines, and more particularly to a system including a pneumatic safety interlock system for ceasing potentially dangerous operations of the machine when the closure member covering the access opening to the machine is opened.

It has been found that the use of pneumatic controls for an article treating machine such as a washing machine in lieu of the presently used electrical controls has many potential advantages, and a pneumatically controlled structure is fully described and claimed in my application Serial No. 36,429, filed on June 15, 1960, and assigned to the General Electric Company, assignee of the present invention. In addition, it is highly desirable to provide appropriate safety features in article treating machines such as washing machines, wherein high speed rotation of an article with substantial mass, such as a wash basket, may be provided.

Accordingly, it is an object of my invention to provide a suitable pneumatic arrangement for preventing opera tion of an article treating machine when the closure member covering the access opening of the machine is opened.

A further more specific object of my invention is to provide a structure wherein a pneumatically operated mechanism which controls the operation of a machine also senses a pressure change when the closure member is removed from the access opening of the machine, and this pressure change in turn causes the control mechanism to shut off the machine.

In one aspect of my invention, I provide an article treating machine in which an article container such as, for instance, a clothes basket is in the usual manner enclosed by a cabinet which has an access opening to the container formed therein. The access opening is closed by any suitable member such as a lid which is movable to either an open or a closed position. I provide suitable means for treating articles which are in the container, and the treating means in turn is operated by suitable drive means which, conventionally, includes an electric motor. In accordance with my invention I cause this motor to operate an air compressor which connects with a conduit leading to the closure member so that the end thereof which is remote from the compressor is closed and opened by the lid in, respectively, its closed and open positions. The operation of the treating means by the drive means is controlled by a suitable enabling means which, in its first position, permits the motor to operate the treating means, but in its second position prevents the motor from operating the treating means. The enabling means is controlled by pneumatic pressure and is connected to the conduit so that when there is a decrease in pressure because the lid has been opened the enabling means moves from its first to its second position thereby shutting oif the machine in response to the opening of the lid.

The subject matter which I regard as my invention is particularly pointed out and distinctly claimed in the concluding portion of this specification. The invention itself, however, both as to its organization and its method of operation, may best be understood by reference to the following description taken in conjunction with the accompanying drawing.

In the drawing, FIGURE 1 is a schematic front elevational representation of a fluid controlled article treating 2,986,910 Patented June 6, 1961 machine, more specifically, in this case, a clothes washing machine; and

FIGURE 2 is a schematic representation of the controlling circuit for the motor which operates the treating means in FIGURE 1.

Referring now to FIGURE 1, I have shown therein an agitator-type clothes Washing machine, generally indicated by the numeral 1, with the conventional basket 2 which may be provided with perforations 3 and is disposed within an outer liquid-retaining imperforate tub or casing 4. The tub 4 and basket 2 are in turn mounted within a casing 5 secured on a base 6 so as to enclose the tub and basket, an access opening 7 being provided so that an operator may reach into the basket 2 for insertion and removal of clothes. The access opening 7 is covered by a suitable closure member such as lid 8 which may, as shown, he provided with hinges 9 pivotably securing it to the top 10 of easing 5. Casing 5 may also include a suitable backsplasher assembly 11 on which is mounted a controlling structure 12 provided with a suitable manual cycle control and indicating structure 13 in the conventional manner.

At the center of basket 2 there is positioned a vertical axis agitator 14 which includes a center post 15 and a plurality of Water circulating vanes 16 joined at their ends by an outwardly flared skirt 17. Both the clothes basket 2 and the agitator 14 are rotatably mounted. The basket is mounted on an outer shaft 18 and the agitator 14 is mounted on an inner shaft 19 which is rotatably secured relative to the outer shaft. During the cycle of operation of the machine 1, it is conventional for, first, the agitator to be oscillated back and forth on its axis in a horizontal plane by rotation of the shaft 19 so as to wash clothes within basket 2 after the introduction of the washing liquid. Then, after a predetermined period of this washing action, the basket 2 is rotated at high speed through shaft 18 to extract centrifugally the washing liquid from the clothes and discharge it to drain, as will be explained. Following this extraction operation, a supply of clean liquid is introduced into the basket for rinsing the clothes and the agitator is again oscillated. Finally, the basket is once more rotated at high speed to extract the rinse water.

The basket 2 and agitator 14 may be driven through any suitable transmission from a motor schematically indicated at 20. Motor 20 drives the basket and agitator through a suitable transmission assembly 21 provided with a pneumatic connection 22 to control 12. Transmission 21 is so arranged that it supports and drives both the agitator drive shaft 19 and the basket mounting shaft 18. When there is no fluid pressure transmitted to trans mission 21 through hose 22, the transmission causes the agitator 14 to oscillate in a substantially horizontal plane within the basket 2. Conversely, when pressure is supplied through hose 22, the transmission rotates the basket 2 and agitator 14 together at high speed for centrifugal extraction. While the specific form of the transmission forms no part of the invention of this application and a detailed description of the transmission would merely complicate the disclosure without clarifying my invention, reference is made to Patent No. 2,462,657, issued to Jacob W. McNairy on February 22, 1949, and owned by the General Electric Company, assignee of the present invention. That patent discloses in detail the structural characteristics of a fluid drive transmission assembly suitable for use in the illustrated machine, the only variation being that I prefer to utilize pneumatic controls rather than electric controls. Since, in the McNairy patent, inflation of a bellows provides spin and deflation thereof provides agitation, it will be obvious that I may effect this result by controlling the pressure transmitted through hose 22 and by connecting the hose to the bel- 3 lows of the McNairy structure. The control of the pressure in hose 22 is briefly discussed herebelow.

In order to introduce fresh water to the machine, suitable conduits 23 and 24 leading respectively to hot and cold water sources (not shown) are provided, and these two conduits lead respectively into a pair of valves schematically shown by the numerals 25 and 26. Valves 25 and 26 control the fiow of hot and cold water respectively into a conduit 27 having an outlet 28 positioned in spaced relationship over an opening 29 formed in the top flange portion 30 of tub 4 so that suitable supplies of hot, cold, or warm water may be introduced in the desired quantities into the tub 4 and basket 2. While such valves are commonly controlled at the present time by electrical means such as solenoids, I prefer, in my contemplated structure, to control the movement pneumatically, and for this purpose I provide air conduits 31 and 32 respectively to valves 26 and 25. The internal structure of valves 25 and 26 does not form a part of the present in vention; however, reference is hereby again made to my aforementioned application Serial No. 36,429 in which there is fully described a valve suitable for the purpose. It is suflicient for present purposes to state that, in accordance with the disclosure of my aforementioned application, each of the valves provides flow when a suitable amount of pressure is provided through the air conduit thereto and prevents flow when this pressure is removed.

Motor 20, in addition to driving transmission 21, is directly connected both to an air compressor 33 and a pumping mechanism 34 so as to drive both the compressor and the pump continuously during its operation. It will readily be understood that both the compressor 33 and the pump 34 may be of a conventional structure well known in the art and that therefore the particular internal construction of each is not described herein.

The operation of compressor 33 by motor 20 causes air to be pulled in and compressed. This relatively high pressure air, which may, for instance, be on the order of p.s.i.g., passes from the air compressor 33 through a conduit 35 into the control member generally indicated at 12. It will be understood that the control 12 may be of the conventional type which is in commercial use in many instances, for instance, in industrial laundering operations. For instance, one such control is briefly described on page 58 of the textbook entitled Industrial Detergency by William W. Niven, Ir., published in 1955 by Rhinehold Publishing Corporation (see the paragraph starting immediately below FIGURE 4-3 on the cited page). In this type of control (not illustrated herein since it is not part of my invenion), a roll of sheet material is positioned in the path of the incoming air from conduit 35, and connections are provided to the different outlets 22, 31, 32 and 37 which come out of the unit 12 and extend to different components of the machine. The roll of material has suitable openings to allow the air under pressure to pas through to the different components at the appropriate times in the cycle (in the manner of a player piano), and is rotated by any suitable means such as a small synchronous motor, schematically indicated by the numeral 39. In his way, the passage of the roll and the position of the openings therein control the functioning of the different components of the machine, causing it to pass through an entire cycle to provide the various operations described above, and then shutting off the machine. Thus, when operation of motor 20 is started to cause compression of air by compressor 33, and operation of motor 39 is also started, the machine will proceed through an entire cycle under the control of the sequence control device 12.

The pump 34 has its inlet connected to a flexible conduit 40, which in turn is connected to an opening 41 formed in the bottom 42 of tub 4 so that water flows from the bottom of the tub 4 down through conduit 40 into pump 34. A conduit 43 is connected to the outlet of 4 a pump 34 and splits into two diiierent portions 44 and 45 leading respectively to valves schematically illustrated at 46 and 47. Valves 46 and 47 respectively have connected to their outlets conduits 48 and 49, and are respectively controlled through air hoses 37 and 50, hose 37 extending directly from control 12 and hose 50 being joined to the control through hose 22. The valves 46 and 47 may be of any conventional pneumatically operated type, and in this connection a suitable valve for this purpose is disclosed in detail in my aforementioned application Serial No. 36,429. As explained therein, the valves 46 and 47 represent structures wherein the provision of air pressure to the valve causes the flow of liquid therethrough to be cut off, and the removal of air pressure permits flow of liquid through the valve.

When the valve 46 is closed and valve 47 is opened, the liquid passing from the tub 4 through pump 34 is passed through the valve 47 to conduit 49 and then out to a suitable drain (not shown) positioned to receive the output from the outlet 51 of conduit 49. However, when valve 47 is closed and valve 46 is opened the water passes from pump 34 through the valve 46 and then through conduit 48 and from the outlet 52 thereof into a filter pan 53 secured on agitator 14 and then back into the basket 2 and tub 4. Such a filtering structure is described in full detail and is claimed in Patent No. 2,481,979, issued on September 13, 1949, to Russell H. Colley and assigned to General Electric Company, assignee of the present invention.

It will thus be seen that with only valve 47 open, the water is removed from the tub and basket and passed to drain, while with the valve 46 only being open, the water is continuously circulated and filtered. It is contemplated, of course, that valve 46 is maintained open and valve 47 closed during washing and rinsing operations so as to retain the water within the tub and basket, and that valve 47 is open and valve 46 is closed during spinning so as to provide for removal of the water being spun out of the clothes contained within the basket 2.

Tub 4 is joined at its lowest section to the transmission 21 by a flexible boot member 54. This permits freely the motion between the tub and the agitator, basket and transmission which frequently occurs during spinning operations, particularly because of unbalanced clothes distribution within the basket 2. It is contemplated that in the conventional manner, although not shown, the tub 4 may be secured to the rigid components of the machine while the basket, agitator, and the components secured to the basket may be flexibly mounted on the rigid compo nents of the machine. Also, of course, all hose and conduit connections extending between rigidly secured parts and flexibly secured parts are preferably flexible in order to allow for relative motion of the parts. 7

Reference is now made to FIGURE 2 in conjunction with FIGURE 1 for a description of the electrical structure within machine 1. In FIGURE 2, the motor 20 is schematically shown as a conventional induction-type motor having a stator with a main winding 55 and a start winding 56 and a rotor schematically indicated by the numeral 57. Rotor 57 is connected to compressor 33 so that when the motor is in operation there is also operation of the air compressor to cause the passage of air under pressure through conduit35 to the various machine components to be operated. The start winding 56 of the motor is connected through a switch 58 controlled by a pneumatic mechanism 59 connected by a conduit 60 to the conduit 35. As fully described in my aforementioned application Serial No. 36,429, the start winding is kept in parallel with main winding 55 during starting of the motor by closure of switch 58 and then, by virture of the pressure provided by the air compressor 33, the switch 58 is opened to break the start winding circuit so that the motor may continue to run on the main winding 55 alone in the conventional manner.

The energizing circuit for motor 20 is provided through a pair of conductors 61 and 62 which are intended to be connected across a suitable source of power (not shown), generally the conventional 110 volt single phase source provided for domestic use. The circuit from conductor 61 extends through the motor 20, and then through a conductor 63 to switch means 64 for enabling the motor 20 to operate the agitator or basket; switch means 64 will be briefly described herebelow, having been fully described and claimed in my aforementioned application Serial No. 36,429. From switch means 64, a conductor 65 is then connected through a switch 66 to conductor 62 to complete the circuit. The timer motor 39 is connected by conductor 67 in parallel with motor 20. The timer controls the opening and closing of switch 66, either through a conventional cam system or through the type of pneumatic system described above in connection with sequence control mechanism 12.

Referring now specifically to the structure of switch means 64, it includes, within an outer rigid casing 68 to which are secured contacts 69 and 69a, a bellows-type device 70 which carries bridging contact 71 for completing the circuit between the contacts 69 and 69a. Together with the front wall 72 of casing 68, the bellows member 70 forms an enclosed chamber. In communication with this enclosed chamber there is a conduit 73 connecting it to conduit 35, and a conduit 74 which leads (as shown in FIGURE 1) up through casing flange 75 so as to terminate in an open portion 76 directly beneath the lid 8. When the lid 8 is in a closed position, as shown, the end 76 of conduit 74 is shut off whereas when the lid is pivoted on hinge 9 so as to provide access to opening 7, the end 76 of conduit 74 is also opened, thereby providing a direct path to atmosphere from the compressor 33 through conduits 35 and 73, the chamber formed by bellows 70 and wall 72, and conduit 74.

Returning again to the description of mechanism 64, the bellows is biased to a collapsed position by a spring 77, and in its collapsed position air may escape from the interior of the bellows through an opening 78 in the bellows and openings 79 in the casing 68. However, when the bellows is pushed to the left against the action of spring 77 by means of a manual member 80, the openings 79 are sealed off so that the only openings to the interior of the bellows are through conduits 73 and 74.

Thus, when the manual member 80 is depressed to cause engagement of bridging contact 71 with contacts 69 and 69a, it completes an energizing circuit for the motor 20 (assuming switch 66 to have been closed). The motor then starts in operation to provide either agitation or spin for the washing machine, and in addition to cause operation of the air compressor 33. When the air compressor starts to operate it provides a pressure within the bellows 70 provided openings 79 are closed and end 76 of conduit 74 is closed by lid 8. In the event that both of these situations prevail, then the operation of the compressor causes an increase in the pressure within the bellows member, and even after member 80 is released the air pressure will retain the bellows in its extended position against the action of spring 77 thereby to keep completion of the circuit in effect and to keep the motor 20 operating the washing machine either for agitation or s m.

As explained in my aforementioned application Serial No. 36,429, should the compressor fail to operate .for any reason the pressure Within the bellows 70 will de crease and the spring 77 will overcome the air pressure to disconnect the motor 20. A particular feature of my present invention is the addition of the conduit 74 arranged in such a way as to make the switch mechanism 64 also sensitive to the opening of lid 8. When the lid is kept in its closed position, the end 76 of conduit 74 is closed and therefore the desired higher pressure may prevail within the bellows 70 to keep it extended against the action of spring 77. If, however, lid 8 should be opened this removes the closure from end 76 of conduit 74 and the pressure of spring 77 overcomes the air pressure and moves the bellows to separate the contacts 69 and 69a. In this manner, by the simple addition of an appropriate conduit, the structure already provided for control of a pneumatically controlled article-treating machine is also efiective to provide a desirable safety feature by which the machine is caused to stop operating should the closure member covering the access opening to the interior of the machine be opened.

Once the lid 8 is re-closed after it has been opened, it is then, of course, merely necessary to depress button in order to start the machine in operation again.

It will be seen from the foregoing that my invention provides an eifective safety interlock by means of which, as a result of a variation in pneumatic pressure caused by opening of the lid 8, the machine may be made to stop operating as a result of such opening of the lid. It will be obvious that variations on this general approach may be made. For instance, the safety structure may readily be made to be inoperative during agitation and only operate during spin, in which event the machine will stop operating only when the lid is raised during spin, but will continue operating when the lid is raised during agitation. Also, while my invention has been shown in connection with a specific type of pneumatic switch which is described and illustrated in my aforementioned application Serial No. 36,429, it may obviously be used in connection with other pneumatic switches and may, in fact, be arranged so that it not only stops operation of the machine when opened but restarts it when closed.

Thus, while in accordance with the patent statutes I have described what at present is considered to be the preferred embodiment of my invention, it will be obvious to those skilled in the art that various changes and modifications may be made therein without departing from the invention, and I therefore aim in the appended claims to cover all such changes and modifications as fall within the true spirit and scope of my invention.

What I claim as new and desire to secure by Letters Patent of the United States is:

1. In an article-treating machine: an article container; means for treating articles in said container; drive means operating said treating means including an electric motor; air compressor means operated by said motor; a cabinet enclosing said container and having an access opening to said container formed therein; a closure member movable to open and closed positions over said opening; conduit means having one end connected to said compressor means and its other end connected to be closed and opened by said closure member in its closed and open positions respectively; enabling means having a first position enabling said motor to operate said treating means and a second position preventing said motor from operating said treating means, said enabling means being pressure controlled and connected to said conduit means so as to be moved from said first to said second position thereof in response to a decrease in the pressure in said conduit means caused by opening of said closure member.

2. The apparatus defined in claim 1 wherein said enabling means is a pneumatically operated electric switch having contacts connected in series with said motor, said contacts being closed in said first position and opened in said second position.

3. In an article-treating machine: an article container; means for treating articles in said container; drive means operating said treating means including an electric motor; air compressor means operated by said motor; a cabinet enclosing said container and having an access opening to said container formed therein; a closure member for said access opening movable to open and closed positions; enabling means including a movable structure having a first position enabling said motor to operate said treating means and a second position preventing said motor from operating said treating means, said structure being biased 7 to its second position, manual means for moving said structure to its first position, and means cooperably positioned relative to said structure to form a closed chamber therewith when said structure is in said first position and to form a vented chamber when said structure is in its second position; conduit means including a first conduit connecting said compressor means to said chamber, and a second conduit connected at one end to said chamber and having its other end positioned to be closed and opened by said closure member in its closed and opened positions respectively, said structure being formed so that the pressure within said chamber when said structure is in its first position and said compressor is operating and said closure member is in its closed position acts on said structure in opposition to the bias thereon to retain said structure in its first position, and so that the bias on said structure moves it to its second position when said compressor ceases to operate or when said closure member is moved to open position.

4. In a clothes washing machine: a receptacle assembly for containing liquid and clothes to be washed; means for washing clothes in said receptacle assembly; drive means operating said washing means including an electric motor; fluid compressor means operated by said motor; a cabinet enclosing said receptacle assembly and having an access opening to said assembly formed therein; a lid for said access opening movable to open and closed positions; conduit means having one end connected to said compressor means and its other end positioned to be closed and opened by said lid in its closed and open positions; switch means having a closed position enabling said motor to operate said washing means and an open position preventing said motor from operating said washing means, said switch means being pressure controlled and connected to said conduit means so as to be moved from said closed to said open position thereof in response to a decrease in the pressure in said conduit means caused by opening of said lid.

Guth May 27, 1958 Bauerlein et a1. Nov. 22, 1960 

